Valve silencer



April 26, 1955 P. L. VERMAIRE 2,706,974

VALVE SILENCER Filed Aug. 25, 1954 3 I INVENT0 fba fi ewzafre Y A ORNEY VALVE SILENCER Paul L. Vermaire, Grand Rapids, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August 25, 1954, Serial No.

8 Claims. (Cl. 123-90) 'ljhis invention has to do with translating motion and taking up lash between driving and driven elements such as the operatlng cams and poppet valves of an internal combustion engine each valve operating cycle.

It is accordingly the object of the invention to provide a construction results which is simple in design and economical to manufacture, and will not get out of The means by out will be more description of an ing reference to the drawing wherein:

Figure 1 is a transverse sectional view through a porparts broken away features in better detail.

Figure 3 is an end view taken in the direction of the arrows 3-3 of Figure 4.

Figure 4 is an enlarged fragmentary view showing the valve operating mechanism in plan.

The engine illustrated in Figure block the rocker assembly cam 11 whose motion is transmitted to the push rod through the tappet 12.

a pivotally oscillated rocker member 13 journalled by a rocker shaft 14. One end 15 of the rocker member has the usual pivotal connection to the push rod afforded by the adjusting screw ball stud 16.

As best shown in Figures 2-4, the opposite end of the rocker 13 is provided with means for journalling a link for pivotal movement substantially in the rocker oscillation. Such means is shown in pin 18 extending across a bifurcation 19 ofrset relation toward the rocker shaft link 17 has 21 depending plane of the the form of a the center of the valve stem end face 21. As indicated by the angle A, this cam surface and end face are slightly divergent to each other when the parts are in valve closed position (shown in solid lines), which in combination with aforementioned offset of the pin 18 causes the link to pivot counterclockwise to the position shown in broken lines during valve opening. For this purpose the cam surface can be made arcuate with its center of curvature at 22 which is eccentric to the axis of the pin 18 by an amount equal to that which 2,706,974 Patented Apr. 26, 1955 the pin 18 is offset from the closed position.

an annular weight 28. Between the bore of the weight 28 and the periphery of the stud 26 a order of .02.03 inch is provided,

stantial clearance likewise exists for freedom of movement of the weight on the stud between the head 27 and the sleeve 30.

Resilient means is provided for biasing pivotal moveof the link 17 about the pin 18 in the counterclockwise direction (as viewed in Figure 2). This resilient faces of the link and bifurcation 19.

In operation, with each lift stroke of the engine cam 11 its motion is transmitted through the tappet 12 and push rod 10 to the rocker 13, causing it to pivot clockwise about its shaft 14 and force the link 18 in a downward direction to open the valve 5. In moving downward, the link is forced to pivot in a direction against the biasing action of 32. On the return spring 7 acts through the stem 8, link move their associated end of the rocker upward against the inertia of the inertia hammer 25.

this respect by delivering light impact loads to the link, sufiicient to overcome frictional drag between rubbing surfaces of the various parts.

While my invention is shown and described with referpersons skilled in the art and gest themselves to the scope of the invention as defined not depart from hereinafter.

I claim:

1. In a motion translating and lash take-up connection including a pivotally oscillated member and a reciprocated the driven direction and is decelerated in the driving direction relative to the speed of movement of said oscillated member, a bracket extending from the link in a direction generally normal to said axis and carrying a Weight adjacent its extended end tending to induce continued pivotal movement 0 the link after termination of each stroke of the reciprocated member, and resilient means acting between sai link and oscillated member to bias their relative pivotal movement in the direction of maintaining engagement of said cam surface with the reciprocated member.

2. In a motion translating and lash take-up connection including a pivotally oscillated member and a reciprocated member in alternate driving and driven relation with each other, a link connected for pivotal movement on said oscillated member about a fixed axis thereon and having a cam surface operatively engaging said reciprocated member, said cam surface having a curvature about an axis eccentric to said pivotal movement whereby movement of the reciprocated member is accelerated in the driven direction and is decelerated in the driving direction relative to the speed of movement of said oscillated member, a bracket extending from the link in a direction oppositely of the pivotal axis of the oscillated member generally normal to said axis and carrying a weight adjacent its extended end tending to induce continued pivotal movement of the link after termination of each and resilient means acting between said link and oscillated member to bias their relative pivotal movement in the direction of maintaining engagement of said cam surface with the reciprocated member.

3. The invention defined by claim 2, in which said weight is loosely carried on said bracket whereby said continued pivotal movement of the link is accentuated by impacts transmitted through the bracket thereto by the weight.

4. In a rocker assembly for operating a poppet valve or the like, a rocker having an arm extending from the rocker axis and provided adjacent its extended end with means for pivotally carrying a link on an axis substantially parallel to the rocker axis, a link journalled to said means and having a depending portion terminating wit a downwardly presenting valve engageable cam surface of arcuate shape whose axis is substantially parallel to and spaced oppositely of the rocker axis from said means, a spring interposed between said rocker and link biasing their relative pivotal movement in the direction of bringing said cam surface closer to the rocker axis, and an inertia hammer operative to deliver impact loads to the link for inducing its pivotal movement against the spring on completion of each valve operating cycle.

5. The invention defined by claim 4, wherein said inertia hammer comprises a weight disposed laterally of said means and a bracket supporting the weight, said bracket being connected to move with the link and said weight having limited freedom of movement relative thereto both in the direction about said means and toward and away therefrom.

6. In a poppet valve operating mechanism including a valve stem having an end face, a valve closing spring stroke of the reciprocated member,

connected to the stem, a rocker assembly operable against said end face to open the valve in opposition to the force of the closing spring, and driving means for the rocker assembly, said rocker assembly including a rocker having one end connected to said driving means and a link pinned to its opposite end for relative pivotal movement about an axis normal to the plane of oscillation of the rocker, said link having a cam surface normally in abutting contact with said stem end face and inclined thereto in a plane normal to said axis at an angle decreasing with pivotal movement of the link during the valve opening stroke, a stud fixed at one end to said link and extending therefrom in the plane of said pivotal movement, a head on the extended end of said stud, a weight loosely fitting the stud adjacent said head, and means on the stud loosely spacing said weight from the link.

7. In a motion translating and lash take-up connection including a pivotally oscillated member and a reciprocated member, a cam element movable on the oscillated member and drivably operating the reciprocated member in response to pivoting of the oscillated member in one direction, an inertia hammer carried by said cam element for inducing its movement out of operative engagement with the reciprocated member upon completion of each return stroke of the reciprocated member, and means resiliently opposing said hammer induced movement of the cam element.

8. In a rocker assembly for operating a poppet valve or the like, a rocker having an arm extending from the rocker axis, a cam element movably mounted on the extended end of said arm having a valve engageable cam surface, said cam surface being disposed relative to the rocker axis such that movement of the cam element during valve opening movement of the rocker effects a lengthening of the distance between the valve engageable portion of the cam surface and said end of the arm, a spring interposed between the cam element and rocker biasing their relative movement in the direction of bringing said cam surface closer to the rocker axis, and an inertia hammer carried by said cam element for inducing its movement against the spring in response to the rocker stopping its movement in the valve closing direction.

References Cited in the file of this patent UNITED STATES PATENTS 1,270,941 Goodwin July 2, 1918 1,411,387 Sulfa Apr.'4, 1922 1,687,911 Vincent Oct. 16, 1928 1,785,523 McLeod Dec. 16, 1930 1,950,590 Berry Mar. 13, 1934 1,994,743 Anderson Mar. 19, 1935 2,365,401 Fisk Dec. 19, 1944 FOREIGN PATENTS 482,153 Germany Sept. 7, 1929 

